"Lithoglyphopsis" aperta, which transmits human Schistosoma sp. of the Mekong River, is one of over 80 snail species of Hydrobiidae endemic in the Mekong River. Detailed functional morphological investigations of this fauna are in progress to delineate genera and species in objective terms, and to delineate their phylogenies particularly with reference to their potential to transmit human schistosomes. Computer analyses of morphological and ecological data are employed to handle a grid of 50 to 60 taxa by at least 100 traits. Both "Q" and "R" mode analyses are made. With these techniques we have clearly pointed out convergences in many shell straits used by Brandt (1968, 1970, 1971) to name many species and genera. We have substantiated the existence of two lineages in Mekong River Hydrobiidae. Studies of faunal diversity at critical places inthe Mekong River are well underway. Ecological factors accounting for changes in diversity are assessed. Correlation of these data with the potential of segments of the fauna to transmit schistosomes will enable knowledgeable advice to the Mekong Committee as related to creation of super dams, river management, and future public health.